1. Field
The inventive concept relates to a semiconductor device and to a method of manufacturing the same. More particularly, the inventive concept relates to a semiconductor device comprising a transistor having a channel region in which a stress has been induced and to a method of manufacturing the same.
2. Description of the Related Art
The width and length of a channel of a MOS transistor are becoming smaller (for both NMOS and PMOS transistors) in response to the growing demands for smaller semiconductor devices. However, it is well known that a reduction in the length of the channel of a MOS transistor increases the likelihood that the device will exhibit certain defective performance characteristics known as short-channel effects.
Improved transistor structures, such as an RCAT (Recess Channel Array Transistor) or a SRCAT (Sphere-shaped Recess Channel Array Transistor), have allowed for greater channel lengths without compromising an overall reduction in size of the transistor. Thus, semiconductor devices may employ an RCAT or SRCAT to prevent short-channel effects, i.e., to ensure a high degree of performance. Regardless, the performance of a MOS transistor is generally compromised if the width of the channel of the MOS transistor is reduced because narrower channels reduce the amount of current flowing through the channel. Ultimately, the scaling down of the MOS transistor will worsen the reliability of the semiconductor device.
With these considerations in mind, instead of looking at ways to further reduce the physical dimensions of the channel, some research in the field has been aimed at increasing the mobility of charge carriers (electrons in the NMOS transistor or holes in the PMOS transistor) by applying a tensile stress or a compressive stress to the channel.